when i was at the headcount meeting two weeks on boston, chris asked me did make some comments on what age he think we want to limit contact. i said i don't know. i wouldn't know how to make that estimate right now. but we know that less is better. we do know that. so the other pieces reducing unnecessary or inappropriate contact. is there a safe contact? ready to understand understand that. i've been accelerometers side its outcome is important to know. so pop warner has been trying this, ideally, nfl. what can we do at our youth level? those are five things we can start to do, but we've got to wrap it around evidence to now begin to many more precisely say coming to know what euros should we doing this. nine euros should be doing this combat should do this. 12 euros should or shouldn't do this. from my perspective that's the direction they move in. >> the virginia tech study shows sun has a pretty big. the study showing there's sub concussive that are hard to measure and little kids suffer is not enough. we need more research, more data -- >> we really need to understand also with on